The present invention relates to weighing dividing machines of the type specially designed for use in dispensing powdered or granulated materials, ensuring that the weight dispensed is correct and allowing use in a continuous process.
The weighing dividing machine is useful both when it is desired to weigh out large quantities, as is the case when bags are to be filled, and also when small bottles are to be filled (of the type used in chemist's shops, for example), a technology with the general dimensions of the equipment varying solely for that purpose.
The increasing scope of hygienic controls over foodstuffs, together with the present day trend toward packaging all types of powdered or granulated products, has resulted in the development of an important packaging technology in recent years, designed to put a determined quantity of product into the appropriate container by processes which are as automated as possible.
This has made it necessary to include in the packaging line an apparatus whose function is to ensure that the quantity put into each container is the correct amount planned for the latter.
At the same time, the significant expansion of the consumers' associations, which are increasingly monitoring the quality and quantity of products, has made it necessary to refine control of the quantities weighed out, in order to attempt to minimize variations in the amounts put into the containers and in any case to keep them within the established standards.
To date, two different types of apparatus have been used to graduate the amount to be put into the container.
The older types are volumetric dispensers, which divide the product as it reaches them into quantities of equal volume. In many cases, however, the varying density of the product over time, temperature changes, etc. prevents the weights from also being equal.
A more recent technological advance is represented by the weighing dispensers, in which control is by weight. These require the presence of a scale or loading cell which accepts the correct quantity of product up to the desired weight, and then delivers the product to a hopper which finally puts it into the container.
The need to maximize the accuracy of the weight put into each container has been causing the volumetric dispensers to fall into disrepute in recent years because of the differences of measure by weight in which their use results, and has been making it necessary to effect the control by means of weighing dispensers. These avoid the above problem, but as a negative consequence result in greater slowness of the production process, which in turn make the process considerably more costly.
Accordingly, it is an object of the present invention to provide a weighing dispenser combining in itself elements coming from the two existing types of dispenser, in other words, from both the volumetric dispenser and the weighing dispenser. It is another object to provide such a device which ensures an accuracy of weight even greater than that obtained with the conventional weiging dispensers, while at the same time providing production rates much higher than those of the latter and close to or even higher than those of the volumetric dispensers.